Beitza 13 - Making mustard
The landlord of Rava bar Rav Chanan asked him a question: is it OK to to crumble mustard pods in order to extract seeds on a Holiday (Yom Tov). Being that cooking is permitted, that too should be allowed; on the other hand, since it could have been done before Yom Tom, maybe it should not be done now?
Rava bar Rav Chanan did not have a ready answer. He went to ask Rava, and Rava told him that it is totally permitted to rub ears of grain and crumble legumes on a Yom Tom, and the answer the query is "yes" - provided it is done with the hands and not a vessel.
Ah! But now we found a case of separating tithe on a Yom Tov. He is, after all, making a small winnowing here, and this is when the obligation of tithe begins. And all our logic on the previous page was based on tithing not being permitted on a Yom Tov!?
How are we to deal with the contradiction? In truth, this too is not a problem. This is a mini-winnowing, and only Rabbi Yehudah the Prince says that it counts. His senior opponent, Rabbi Yose the son of Rabbi Yehudah, says that even after hand winoowing there is still no obligation to tithe, and one can freely snack on the food thus obtained. Thus, our previous logic is justified, and we know how to make mustard.
Art: Winnowing by William Edward Millner